Yarn plating method and apparatus for circular knitting machines

ABSTRACT

The yarn feed device is adapted to simultaneously feed elastic and non-elastic yarns to the needles of the knitting machine and at predetermined ratios relative to each other. A yarn feed roller is drivingly rotated by the non-elastic yarn as the yarn is consumed by the needles in forming the stitch loops of a knit fabric. The elastic yarn is in engagement with the roller and is fed to the knitting machine needles at a predetermined ratio, relative to the non-elastic yarn. Three different types of yarn feed rollers are disclosed, each being provided with yarn receiving grooves which may be of different diameters so that the yarns are fed at different ratios or under different degrees of tension.

United States Patent 1 1 Carswell [111 3,800,564 1- Apr. 2, 1974 [75]lnventorz Theodore R. Carswell, Drexel, NC.

[73] Assignee: Pilot Research Corporation, Valese,

[22] Filed: Oct. 13, 1971 121] App]. No.: 188,808

Related US. Application Data [63] Continuation-impart of Ser. No.89,565, Nov. 16,

1970, abandoned.

[52] US. Cl. 66/136, 66/132 R, 66/146 [51-] Int. Cl D041) 9/34 [58]Field of Search 66/136, 137, 132, 146,

66/132 R, 125 R; 242/155 R, 47.01; 112/254 [56] 9 References CitedUNITED STATES PATENTS 1,124,827 .1/1915 White et a1. I; 242/155 R2,972,245 2/1961 York et al 66/146 FOREIGN PATENTS OR APPLICATIONS1,151,630 7/1963 Germany 66/132 R 603,308 6/1948 Great Britain I 66/146770,037' 3/1957 Great Britain 242/155 R 135,569 7/1960U.S.S.R........... 66/132 R 1,550,273 11/1968 France 66/132 PrimaryExaminer-Robert R. Mackcy [57] ABSTRACT The yam feed device is adaptedto simultaneously feed elastic and non-elastic yarns to the needles ofthe knitting machine and at predetermined ratios relative to each other.A yarn feed roller is drivingly rotated by the non-elastic yarn as theyarn is consumed by the needles in forming the stitch loops of a knitfabric. The elastic yarn is in engagement with the roller and is fed totheknitting machine needles at a predetermined ratio, relative to thenon-elastic yarn. Three different types of yarn feed rollers aredisclosed, each being provided with yarn receiving grooves which may beof different diametersso that the yarns are fed at different ratios orunder different degrees of tension.

PATENIEBAPR 21914 3.800.564

SHEET 1 OF 2 INVENTOR: THErObORE' \2. CARSWELL ATTORNEY$ YARN PLATINGMETHOD AND APPARATUS FOR CIRCULAR KNITTING MACHINES This application isa continuation-in-part of my copending application, Ser. No. 89,565,filed Nov. 16, 1970, now abandoned, and relates generally to a methodand apparatus for simultaneously feeding two or more yarns to the yarnguide means of a knitting machine.

More particularly, the present method and apparatus is adapted to feedan elastic yarn at the desired rate, relative to the rate at which anon-elastic yarn is consumed by the knitting machine. The non-elasticyarn acts as a driving'means for rotating a yarn feed roller and theelastic yarn is fed to the machine'at the desired rate by the rotationimparted to the yarn feed roller by the non-elastic yarn.

Different types of yarn feeding devices'have been proposed for use withknitting machines. Many of these 7 feed devices include a roller foreach yarn which is driven by direct connection with a driven part of theknitting m-achine'so'that the'feed roller is driven at a predeterminedrate, relative to the driving speed of the knitting machine. This typeof feed device operates satisfactorily when the machine is knitting thesame size stitch throughout the article. However, this type of feeddevice does not include means to vary the amount of yarn fed tocompensate for variation in the size of the stitch loops being formedduring fashioning. Other together in plated relationship, particularlywhen the knitting machine is producing articles which require theformation of stitch loops of various sizes. The difficulty of feedingelastic yarn, particularly uncovered spandex, is increased because thistype of yarn will not unwind from the supply package in an even anduniform manner so that the tension and stretched condition of the yarnconstantly varies. Spandex yarn is difficult to unwind from the supplypackage because it tends to stick to itself and the endmost windscontract so that the wound layers overlap each other.

In most cases, various types of tension devices are relied upon tocontrol the plating relationship of two years as they are fed to theknitting machine so that one yarn is fed to the needles in a certainrelationship with the other yarn and appears on one face of the fabricwhile the other yarn appears on the other face of the fabric. A constantrelationship of tension is difficult to maintain because these tensiondevices may accummulate lint and cause a variation in tension betweenthe two yarns. This constant variation in tension on the yarns isparticularly difficult to maintain when one of the yarns is an elasticyarn and the other yarn is an nonelastic yarn. A150,. it may not bepossible to knit the elastic yarn in the fabric under the desired degreeof relaxation. For example, when covered or uncovered rubber or spandexis fed and knit with a nylon or cotton yarn, any tension applied to theelastic yam will cause a certain stretching of this yarn so that theknit fabric will be drawn inwardly to a degree, which is undesirable inmany cases.

With the foregoing in mind, it is an object of the present invention toprovide a method and apparatus for feeding a plurality of yarns to aknitting machine which is simple to attach to existing knitting machinesof various types and which operates to maintain the desired feedingrelationship of the yarns to each other uniform and constant as they areknit in the fabric, both when knitting fabric with uniform size stitchloops, and when knitting fabric having different sizes of stitch loopsin different portions thereof.

In accordance with this invention, non-elastic yarn is used as a measureor standard to determine the length of the elastic yarn knitted with it,whereby the ratioof the two yarns is maintained constant notwithstandingother variables. To this end, rotatable feed roller means is providedwherein the non-elastic yarn extends around the roller in drivingrelationship to rotate the roller means, and the elastic yarn isextended around the roller in driven relationship. This results in thelength of elastic yarn always-remaining constant relative to the lengthof non-elastic yarn as they are both being knit into the same stitchloops in the fabric.

In one embodiment of the invention, the feed roll means comprises asingle roller with spaced apart peripheral grooves for receiving wrapsof the yarns. The diameters of these yarn receiving grooves may bevaried to feed one or more additional yarns at different rates from thenon-elastic yarn which drivingly rotates the roller. The feed roller ispreferably positioned closely adjacent the yarn feed finger of theknitting machine so that the feeding rate of the yarns from the rollerto the yarn feed finger and to th needles is not affected by passingover guides, through tension devices,

etc.

In another embodiment of the invention, the feed roll means comprises aroller having one relatively narrow peripheral groove for receiving thenon-elastic yarn and a spaced apart relatively wide peripheral portionor groove for receiving the wraps of the elastic yarn so that theelastic yarn does not engage itself as it is driven by the feed roller.Suitable guides are provided at opposite sides of the feed roller formaintaining the wraps of elastic yarn separate from each other.

In another embodiment of the invention, the feed roll means comprises apair of spaced apart rollers, each being provided with a plurality ofspaced apart peripheral grooves for receiving the yarns wrappedtherearound. The non-elastic yarn still operates to drive both of theyarn feed rolls at the rate at which the non-elastic yarn is consumed bythe knitting machine and the elastic yarn is driven in the proper ratioby the rotation of the feed rolls.

It is preferred that some type of brake means be provided to control therotational speed of the yarn feed roller or rollers. The brake meansalso is effective to stop rotation of the feed roller when the yarns areno longer being fed to the knitting machine. When feeding a relativelyheavy non-elastic yarn, rotation of the feed roller is stopped when thenon-elastic yarn is no longer being fed.

Other objects and advantages of the invention will become apparent inthe specification and the claims FIG. 1 is a fragmentary isometric viewof a portion of the lower cylinder of a Komet type circular knittingmachine and illustrating one form of the present yarn feeding deviceassociated therewith;

FIG. 2 is an enlarged vertical sectional view through the yarn feedroller, showing one of the yarns drivingly engaging one of the yarnreceiving grooves therein;

FIG. 3 is an isometric view of a looped yarn illustrating the manner inwhich the yarn is wrapped around the feed roller;

FIG. 4 is a front elevational view of the feed roller;

FIG. 5 is a longitudinal sectional view taken substantially along theline 5-5 in FIG. 4 and illustrating the manner in which the feed rolleris supported for rotatron;

FIG. 6 is an elevational view of a modified form of feed roller andillustrating the manner in which the yarns engage the feed roller;

FIG. 7 is an enlarged view taken substantially along the line 77 in FIG.6, the upper portion being shown in cross-section and the lower portionbeing shown in elevation;

FIG. 8 is an isometric view of another modified form of feed roll meansincluding a pair of feed rollers and illustrating the manner in whichthe elastic and nonelastic yarns are wrapped aboutthe two rollers to befed to the knitting machine;

FIG. 9 is a front elevational view of the feed rollers shown in FIG. 8;and

FIG. 10 is a enlarged fragmentary view of a portion of a typical knitfabric illustrating elastic and nonelastic yarns knit in platedrelationship.

The various embodiments of the feed rolls illustrated in FIGS. l5, 6 and7, and 8 and 9 may each be utilized with various types of knittingmachines and are preferably used where it is desired to knit elastic andnonelastic yarns in plated relationship in the knit fabric. This type ofknit fabric has been particularly difficult to produce with the correctlength of uncovered spandex yarn in the fabric and with the spandexstretched to th proper degree throughout the fabric.

I As illustrated in FIG 1, the feed roll means includes a single feedroller, broadly referred to at R, which is illustrated in associationwith a circular hosiery knitting machine ofthe Komet type having a lowerneedle cylinder 10 with double ended latch needles 11 supported forvertical sliding movement therein. An upper needle cylinder not shown,is supported in axial alignment above the lower cylinder 10 and themachine is provided with suitable stitch cams, not shown, for operatingthe needles in either cylinder to selectively form plain or ribbedfabric. Yarn guide means, in the form of a yarn feed finger 12, isprovided for directing one or more yarns to the needles 11 to be formedinto stitch loops of the knit fabric. In the present instance, the yarnfeed finger 12 is provided with a pair of yarn guide openings or eyes13, 14 so that yarns fed thereto will be simultaneously fed to the hooksof the needles 11, and form stitch loops with the two yarns in platedrelationship to each other, in the manner illustrated in FIG. 10 andwhich will be presently described.

In the embodiment illustrated in FIGS. 1-5, the feed roller R issupported for rotation on a reduced shaft portion by spaced ballbearings 21, 22 (FIG. 5) and held in position thereon by a pair of locknuts 23. The inner race of the ball bearing 21 rests against a shoulderformed at the junction of a support shaft 25 and the reduced shaftportion 20. The inner lock nut 23 bears against the inner race of thebearing 22 to thereby pre vent endwise movement of the roller R on thereduced shaft portion 20 and to permit free rotation of the roller R. Abrake disc 26 surrounds the support shaft 25 and its inner planarsurface engages the end surface of the roller R. A compression spring 27surrounds the shaft 25 and one end engages the outer surface of thebrake disc 26. The other end of the compression spring 27 engages acollar 30 which is supported for longitudinal adjustment on the shaft 25by a set screw 31. Movement of the collar 30 toward the roller Rincreases the force of the compression spring 27 against the brake disc26 and thereby produces an increased braking effeet on the roller R.Movement of the collar 30 away from the roller R will decrease thebraking effect of the brake disc 26 against the roller R and the brakingeffect may be completely eliminated with sufficient movement of thecollar 30 away from the roller R.

The support shaft 25 is bent at a right angle and is supported adjacentits free end in the lower portion of a support post 32 (FIG. 1), thelower end of which is suitably supported on a bed plate, not shown ofthe knitting machine. The illustrated supporting means of the roller Ris merely representative of one of many different types of supportingmeans which may be provided, depending upon the type of machine withwhich the roller R is to be employed.

The roller R is provided with a first yarn receiving peripheral groove35 (FIGS. 4 and 5) for receiving a nonelastic yarn Y-l wrapped one timethereabout, as illustrated in FIGS. 2 and 3. A second spaced peripheralyarn feeding groove 36 is provided on the roller- R for receiving anadditional yarn Y-2 which is preferably elastic, such as raw spandex orthe like, and which is preferably wrapped one time thereabout.

The yarn feed roller R has been found to be of particular value in theknitting of ribbed socks on a Komet type hosiery knitting machinewherein the leg and foot portion of the sock are knitting with the yarnY-l being a 24/2 count (50 percent dacron and 50 percent cotton),non-elastic yarn and the yarn Y-2 being a 40 denier uncovered spandex ofthe type sold under the tradename LYCRA. These two yarns are withdrawnfrom suitable supply packages, not shown, and directed through the usualyarn tension devices and guides downwardly to the feed roller R wherethey are lapped with one turn in respective yarn' receiving grooves 35,36 and then directed forwardly through the yarn guide eyes 13, 14 of theyarn feed finger 12. In this manner, both yarns are simultaneously fedto the same needles at a knitting station of the machine to form stitchloops with the yarns (-1 and Y-2 in plated relationship.

As the needles ll comsume the non-elastic yarn Y-l in forming the stitchloops, this non-elastic yarn Y-l acts as a driver'to impart rotation tothe roller R at a predetermined rate. The rate at which the roller R isrotated by the yarn Y-l depends upon the speed of operation of themachine, the size of stitch loops being knit, and the diameter of theyarn engaging peripheral groove 35. With rotation of the roller R theuncovered spandex yarn Y-2 is positively fed by the roller R to theneedles at a predetermined ratio relative to the nonelastic yarn Y-1 andunder the desired degree of ten sion so that it assumes the properplated relationship with the non-elastic yarn Y-l as stitch loops aresimultaneously formed from both yarns. As illustrated in FIG. 10, theproper feeding of the non-elastic yarn Y-l and the elastic yarn Y-2insures that the plated stitch loops of each yarn will be maintained inthe same relationship throughout the knit fabric. Also, the length ofelastic yarn Y-2 will always remain in the proper proportion and ratioto the length of non-elastic yarn Y-l in the fabric.

The relative rate of speed and the tension of the clastic yarn Y-2 isdetermined by the diameter of the yarn receivinggroove 36 and by theamount of tension initially placed on the elastic yarn between theroller R and the needles ll of the knitting machine. The feeding ratiobetween the non-elastic yarn Y-l and the elastic yarn Y-2 may be variedby varying the diameter of the yarn receiving groove 35, relative to thediameter of the yarn receiving groove 36. It is to be understood thatthis ratio may vary throughout a wide range, depending upon the resultdesired in the knit fabric. In any event, this feeding relationshipbetween the elastic yarn and the non-elastic yarn will be maintained,throughout the knitting of the article; regardless of the size of stitchloops being formed. For example, when the length of the stitch loopsbeing formed is increased, a greater length of non-elastic yarn Y-l willbe drawn into the knitting machine and the roller R will be rotated at afaster rate so that the length of the elastic yarn Y-Z will be increasedby the same amount.

The embodiment ofthe feed roller means shown in FIGS. 6.and 7 may alsobe utilized with the knitting of two or more yarns in any desired typeof knitting machine and is substantially identical to the feed rollmeans shown in the first embodiment illustrated in FIGS. 1-5, exceptthat the wraps of the elastic yarn are maintained separate from eachother so that there is less tendency for the yarn to become wound aboutthe feed roller. Since many parts of the feed roller illustrated inFIGS. 6 and 7 are identical to the parts illustrated in FIGS. l-5, thesame reference characters will be applied to corresponding parts with teprime notation added.

The roller R is supported for rotation on a reduced shaft portion byspaced ball bearings 21, 22' (FIG. 7) and held in position thereon by apair of lock nuts 23. The inner race of the ball bearing 21 restsagainst a shoulder formed at the junction of a support shaft 25 and thereduced shaft'portion 20'. The inner lock nut 23 bears against the innerrace of the bearing 22 to thereby preventendwise movement of the rollerR on the reduced shaft portion 20 and to permit free rotation of theroller'R.

A brake disc 26 surrounds the support shaft 25 and itsinner planarsurface engages the end surface of the roller R. A compression spring 27engages a collar 30 which is supported for longitudinal adjustment onthe shaft 25 by a set screw 31. Movement of the collar 30 toward theroller R increases the force of the compression spring 27 against thebrake disc 26' and thereby produces an increased braking effect of theroller R. Movement of the collar 30' away from the roller R willdecrease the braking effect of the brake disc 26 against the roller Rand the braking effect may be completely eliminated with sufficientmovement of the collar 30 away from the roller R.

A yarn guide support plate is held in position by anut 40a on thethreaded end of the shaft 20 and opposite end portions support the outerends of suitable yarn guide eyes 41, 42. The guide eyes 41, 42 areoffset (FIG. 6) so that the elastic yarn Y2 does not engage itself as itis wound about the roller R. Y

The roller R is provided a first yarn receiving peripheral groove 35'(FIGS. 6 and 7) for receiving a nonelastic yarn Y-l wrapped one turnthereabout, as illustrated in FIG. 6. A second spaced peripheral yarnfeeding groove 36is provided on the roller R for receiving the elasticyarn Y-2which is preferably wrapped one turn thereabout. However, itwill be noted that the yarn receiving groove 36 is much wider than theyarn receiving groove 36 in the first form of feed roller and the yarnguides 41, 42 direct the yarn Y-2 coming into and leavingthe groove sothat the incoming and outgoing portions of the yarn Y-2' do not touch asthey pass around the relatively wide groove 36. Also, the surface of therelatively wide receiving groove 36 is preferably roughened, as by sandblasting or the like, to provide a frictional surface on which theelastic yarn Y-2 is re- I ceived. If desired, the surface engaged by theelastic yarn Y-2' may be in the form of a chrome plated sleeve having amatte finish. n

In the embodiment illustrated in FIGS. 8 and 9, a pair of yarn feedrollers,.indicated at R-1 and R-2, are supported on a suitable bracket45 and in spaced apart, vertical alignment. The upper and lower rollersR-l, R-2 are identical except that the lower roller R-2 is smaller indiameter than theupper roller R-1 and each of the rollers is providedwith a plurality of yarn receiving grooves 46 therein. The upper andlower rollers are supported on shafts 47, 48 which are fixed at one endon the bracket 45 and support ball bearings, not shown, for rotatablysupporting the rollers thereon. Braking means is also provided for bothof the rollers and includes respective brake discs 50, 51 which bearagainst the ends of the rollers and are adjustable by means ofcompression springs 52, 53. n

As illustrated in FIGS. 8 and 9, a non-elastic yarn Y1" is withdrawnfrom a yarn supply source, not shown, and is directed downwardly througha yarn guide eye 55 in the upper end of the support bracket 45 andpassesdownwardly in engagement with one of the grooves 46 in the upperroller R-l, downwardly beneath the lower roller -R-2 and around one ofthe grooves 46 therein, then upwardly over and through a groove in theupper roller R-1, and downwardly in engagement with a groove 46 in thelower roller R2. The elastic yarn Y-2 is also withdrawn from a suitablesupply source, not shown, passes downwardly through a yarn guide eye 56in the support bracket 45, downwardly through a groove in theupperroller R-l, beneath the lower roller R-2 and around in one of thegrooves 46, then upwardly and over and through one of the grooves in theupper roller R-l, and downwardly through one of the grooves in the lowerroller R 2, and then to the knitting machine.

In this embodiment, the non-elastic yarn Y-l still acts as the driverfor rotating both of the upper and lower rollers R-1 and R2 and theelastic yarn Y-2" is fed to the knitting machine to be knit in platedrelationship in an amount which is determined by the speed of movementof the non-elastic yam Y-l and the speed of the rollers R-1 and R-Z.Also, the length and tension under which the elastic yarn Y-2 is knit isdirectly controlled by the speed of movement of the non-elastic yarnY-1. With this double roll arrangement, the

yarns Y-l and Y-2" do not contact each other as they are woundthereabout so that there is no chance that the yarns will stick togetherand wind up on the rollers R-l or R-2.

The fabric in FIG. 10 is shown as it would appear when looking at theinside face and each of the stitch loops in wales W] and W-2 and coursesC-1 and C-2 contains a strand of the non-elastic yarn Y-l and theelastic yarn Y-2, with each of these yarns having been fed to the stitchloops in the desired relationship, relative to each other. In thepresent instance, the elastic yarn Y-2 is maintained inside of thenon-elastic .yarn Y-l so that only the non-elastic yarn Y-l is visiblefrom the outside face of the fabric. If the size of the stitch loops isvaried by the knitting machine, a greater or lesser length ofnon-elastic yarn Y-l will be drawn into each stitch loop which is knitand, since the length of the elastic yarn in the fabric is controlled bythe length of the non-elastic yarn, the length of the nonelastic yarnY-2 will also be varied in the correct proportion.

Thus, in each embodiment of the present invention,

.the feed roller means is rotated by the non-elastic yarn and one ormore elastic yarns are fed at a predetermined rate relative to thenon-elastic yarn which rotates the feed roller means. Therefore, anyvariations in consumption of the non-elastic yarn by the knittingmachine will automatically vary the rotational speed of the feed rollermeans and correspondingly vary the rate of feed of the elastic yarn sothat the predetermined variations in feed rate between the yarns willremain constant. I

Although several embodiments of the feed roller means are illustrated inthe present application, it is understood that other types of feed rollmeans may also be utilized. The feed rollers may be coated with varioustypes of material to aid in frictional engagement of the yarn therewith,to increase the wear resistance of the rollers, and/or to prevent thebuild-up of static, lint, and the like. Also, in certain instances, itmay be desirable to feed yarns of like characteristics to obtain evenfeeding of the yarn. Therefore, although the terms elastic andnon-elastic are used herein, they are intended to include yarns whichare both non-elastic, yarns which are both elastic, or yarns in whichone yarn may be more elastic than the other.

In the drawings and specification, there has been set forth a preferredembodiment of the invention, and although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation.

That which is claimed is:

1. In a knitting machine including needles and yarn guide means fordirecting an elastic yarn and a nonelastic yarn to said needles to beknit in plated relationship into stitch loops of a knitted fabric, thecombination therewith of yarn feeding means comprising rotatable meanspositioned in advance of saidyarn guide and adapted to be driven by saidnon-elastic yarn wrapped thereabout. and said rotatable means drivinglyengaging said elastic yarn for feeding said elastic yarn to said yarnguide means and said needles at a predetermined ratio relative to saidnon-elastic yarn so that said elastic yarn is constantly delivered tosaid needles and is stretched to the desired degree as long as 8 saidrotatable means is being driven by said non-elastic yarn.

2. Yarn feeding means according to claim 1 wherein said rotatable meanscomprises at least one rotatable roller.

3. Yarn feeding means accordingto claim 2 including brake meanssupported adjacent said one roller and engageable therewith forretarding rotation of said one roller.

4. Yarn feeding means according to claim 3 wherein said brake meanscomprises a brake disc in engagement with one end of said one roller, acompression spring supported for engagement at one end with said brakedisc, and adjustment means at the other end of said spring for varyingthe pressure of said spring against said brake disc to thereby vary thebraking forceagainst said one roller.

5. Yarn feeding means according to claim 2 wherein said one roller has afirst peripheral groove for receiving said non-elastic yarn wrappedthereabout.

6. Yarn feeding means according to claim 5 wherein said one roller has asecond peripheral groove spaced from said first groove for receivingsaid elastic yarn wrapped thereabout. 1

7. Yarn feeding means according to claim 6 wherein said first and secondgrooves are of the same width.

8. Yarn feeding means according to claim 6 wherein said second groove issubstantially wider than said first groove and including yarn guidemeans adjacent opposite sides of said wide groove to prevent the wrapsof said elastic yarn from engaging each other.

9. Yarn feeding means according to claim 1 wherein said rotatable meanscomprises first and second rotatable rollers, and including supportmeans for maintaining said rollers in space apart position, and each ofsaid rollers having a plurality of peripheral grooves for receiving andmaintaining said one yarn and said additional yarn separate as they arewrapped at least one time about said rollers.

10. Yarn feeding means according to claim 9 including brake meanssupported adjacent at least one of said rollers and engageable therewithfor retarding rotation of said one roller. v

11. Yarn feeding means according to claim 10 including brake meanssupported adjacent each of said first and second rotatable rollers.

12. A method of feeding yarns to'the needles of a knitting machinecomprising the steps of knitting fabric while forming stitch loops of anelastic yarn and a nonelastic yarn in plated relationship and while,directing said non-elastic yarn around rotatable means in its path oftravel to the needles to impart rotation to said rotatable means at apredetermined rate relative to the rate at which said non-elastic yarnis consumed in forming the stitch loops of the knitted fabric, anddirecting said elastic yarn around said rotatable means in its path ofmovement to the needles to feed said elastic yarn to said needles inaccordance with the rate of rotation of said rotatable means as it isrotated by said non-elastic yarn so that said elastic yarn is constantlydelivered to said needles and is stretched to the desired degree as longas said rotatable means is being driven by said non-elastic yarn.

1. In a knitting machine including needles and yarn guide means fordirecting an elastic yarn and a non-elastic yarn to said needles to beknit in plated relationship into stitch loops of a knitted fabric, thecombination therewith of yarn feeding means comprising rotatable meanspositioned in advance of said yarn guide and adapted to be driven bysaid non-elastic yarn wrapped thereabout, and said rotatable meansdrivingly engaging said elastic yarn for feeding said elastic yarn tosaid yarn guide means and said needles at a predetermined ratio relativeto said non-elastic yarn so that said elastic yarn is constantlydelivered to said needles and is stretched to the desired degree as longas said rotatable means is being driven by said nonelastic yarn.
 2. Yarnfeeding means according to claim 1 wherein said rotatable meanscomprises at least one rotatable roller.
 3. Yarn feeding means accordingto claim 2 including brake means supported adjacent said one roller andengageable therewith for retarding rotation of said one roller.
 4. Yarnfeeding means according to claim 3 wherein said brake means comprises abrake disc in engagement with one end of said one roller, a compressionspring supported for engagement at one end with said brake disc, andadjustment means at the other end of said spring for varying thepressure of said spring against said brake disc to thereby vary thebraking force against said one roller.
 5. Yarn feeding means accordingto claim 2 wherein said one roller has a first peripheral groove forreceiving said non-elastic yarn wrapped thereabout.
 6. Yarn feedingmeans according to claim 5 wherein said one roller has a secondperipheral groove spaced from said first groove for receiving saidelastic yarn wrapped thereabout.
 7. Yarn feeding means according toclaim 6 wherein said first and second grooves are of the same width. 8.Yarn feeding means according to claim 6 wherein said second groove issubstantially wider than said first groove and including yarn guidemeans adjacent opposite sides of said wide groove to prevent the wrapsof said elastic yarn from engaging each other.
 9. Yarn feeding meansaccording to claim 1 wherein said rotatable means comprises first andsecond rotatable rollers, and including support means for maintainingsaid rollers in space apart position, and each of said rollers having aplurality of peripheral grooves for receiving and maintaining said oneyarn and said additional yarn separate as they are wrapped at least onetime about said rollers.
 10. Yarn feeding means according to claim 9including brake means supported adjacent at least one of said rollersand engageable therewith for retarding rotation of said one roller. 11.Yarn feeding means according to claim 10 including brake means supportedadjacent each of said first and second rotatable rollers.
 12. A methodof feeding yarns to the needles of a knitting machine comprising thesteps of knitting fabric while forming stitch loops of an elastic yarnand a non-elastic yarn in plated relationship and while, directing saidnon-elastic yarn around rotatable means in its path of travel to theneedles to impart rotation to said rotatable means at a predeterminedrate relative to the rate at which said non-elastic yarn is consumed informing the stitch loops of the knitted fabric, and directing saidelastic yarn around said rotatable means in its path of movement to theneedles to feed said elastic yarn to said needles in accordance with therate of rotation of said rotatable means as it is rotated by saidnon-elastic yarn so that said elastic yarn is constantly delivered tosaid needles and is stretched to the desired degree as long as saidrotatable means is being driven by said non-elastic yarn.